##### http://autoconf-archive.cryp.to/ac_prog_cc_strict_prototypes.html
#
# OBSOLETE MACRO
#
#   Use AX_CFLAGS_STRICT_PROTOTYPES.
#
# SYNOPSIS
#
#   AC_PROG_CC_STRICT_PROTOTYPES(substvar [,hard])
#
# DESCRIPTION
#
#   Try to find a compiler option that warns when a function prototype
#   is not fully defined. Enable it only if the the system headers are
#   reasonably clean with respect to compiling with strict-prototypes.
#
#   The sanity check is done by looking at sys/signal.h which has a set
#   of macro-definitions SIG_DFL and SIG_IGN that are cast to the local
#   signal-handler type. If that signal-handler type is not fully
#   qualified then the system headers are not seen as strictly
#   prototype clean.
#
#   Currently this macro knows about GCC. hopefully will evolve to use:
#   Solaris C compiler, Digital Unix C compiler, C for AIX Compiler,
#   HP-UX C compiler, and IRIX C compiler.
#
# LAST MODIFICATION
#
#   2006-10-13
#
# COPYLEFT
#
#   Copyright (c) 2006 Guido U. Draheim <guidod@gmx.de>
#
#   This program is free software; you can redistribute it and/or
#   modify it under the terms of the GNU General Public License as
#   published by the Free Software Foundation; either version 2 of the
#   License, or (at your option) any later version.
#
#   This program is distributed in the hope that it will be useful, but
#   WITHOUT ANY WARRANTY; without even the implied warranty of
#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
#   General Public License for more details.
#
#   You should have received a copy of the GNU General Public License
#   along with this program; if not, write to the Free Software
#   Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
#   02111-1307, USA.
#
#   As a special exception, the respective Autoconf Macro's copyright
#   owner gives unlimited permission to copy, distribute and modify the
#   configure scripts that are the output of Autoconf when processing
#   the Macro. You need not follow the terms of the GNU General Public
#   License when using or distributing such scripts, even though
#   portions of the text of the Macro appear in them. The GNU General
#   Public License (GPL) does govern all other use of the material that
#   constitutes the Autoconf Macro.
#
#   This special exception to the GPL applies to versions of the
#   Autoconf Macro released by the Autoconf Macro Archive. When you
#   make and distribute a modified version of the Autoconf Macro, you
#   may extend this special exception to the GPL to apply to your
#   modified version as well.

AC_DEFUN([AC_PROG_CC_STRICT_PROTOTYPES], [
  pushdef([CV], ac_cv_prog_cc_strict_prototypes)dnl
  hard=$2
  if test -z "$hard"; then
    msg="C to warn at nonstrict prototypes"
  else
    msg="C to require strict prototypes"
  fi
  AC_CACHE_CHECK($msg, CV, [
  cat > conftest.c <<EOF
#include <sys/signal.h>
int main (void)
{
   if (signal (SIGINT, SIG_IGN) == SIG_DFL) return 0;
   return 1;
}
EOF

  dnl GCC
  if test "$GCC" = "yes"; then
    if test -z "$hard"; then
      CV="-Wstrict-prototypes"
    else
      CV="-fstrict-prototypes -Wstrict-prototypes"
    fi

    if test -n "`${CC-cc} -c $CV conftest.c 2>&1`" ; then
      CV="suppressed...sys/stat.h"
    fi

  dnl Solaris C compiler

  dnl HP-UX C compiler

  dnl Digital Unix C compiler

  dnl C for AIX Compiler

  dnl IRIX C compiler

  fi
  rm -f conftest.*
  ])
  if test -z "[$]$1" ; then
    if test -n "$CV" ; then
      case "$CV" in
        *...*) $1="" ;; # known but suppressed
        *)  $1="$CV" ;;
      esac
    fi
  fi
  AC_SUBST($1)
  popdef([CV])dnl
])
